diff --git a/src/encrypt.c b/src/encrypt.c
index 8711476..d3ba736 100644
--- a/src/encrypt.c
+++ b/src/encrypt.c
@@ -150,6 +150,7 @@ output_clicked(GtkButton *button, gpointer data)
                                       NULL);
     gtk_file_chooser_set_filename(GTK_FILE_CHOOSER(dlg), yki->output_filename);
     gtk_file_chooser_set_current_name(GTK_FILE_CHOOSER(dlg), yki->output_basename);
+    gtk_file_chooser_set_do_overwrite_confirmation(GTK_FILE_CHOOSER(dlg), TRUE);
 
     if ( gtk_dialog_run(GTK_DIALOG(dlg)) == GTK_RESPONSE_ACCEPT ) {
         g_free(yki->output_filename);
@@ -222,6 +223,29 @@ create_encrypt_dialog(yki_encrypt_data_t *yki)
     return GTK_DIALOG(gtk_builder_get_object(builder, "dlgEncrypt"));
 }
 
+static int
+confirm_overwrite(GtkWindow *parent, yki_encrypt_data_t *yki)
+{
+    GtkWidget *dlg;
+    int ret;
+
+    dlg = gtk_message_dialog_new(parent, GTK_DIALOG_MODAL, GTK_MESSAGE_QUESTION, GTK_BUTTONS_NONE,
+                                 "A file name \"%s\" already exists. "
+                                 "Do you want to replace it?", yki->output_basename);
+    gtk_message_dialog_format_secondary_text(GTK_MESSAGE_DIALOG(dlg),
+                                             "Replacing it will overwrite its contents.");
+    gtk_dialog_add_buttons(GTK_DIALOG(dlg),
+                           "Cancel", GTK_RESPONSE_CANCEL,
+                           "Replace", GTK_RESPONSE_OK,
+                           NULL);
+
+    ret = gtk_dialog_run(GTK_DIALOG(dlg)) == GTK_RESPONSE_OK;
+
+    gtk_widget_destroy(dlg);
+
+    return ret;
+}
+
 
 
 /* Dealing with public keys. */
@@ -356,7 +380,12 @@ yki_encrypt(gpgme_ctx_t gpgme, const char *file, GError **error)
     if ( ret && gtk_dialog_run(dlg) == GTK_RESPONSE_OK && yki_can_encrypt(yki) ) {
         gpgme_set_armor(gpgme, yki.armored);
 
-        ret = gpgutil_open_file(file, "r", &in, error);
+        /* Check with user before overwriting a file with the default filename. */
+        if ( g_file_test(yki.output_filename, G_FILE_TEST_EXISTS) && ! yki.output_filename_userset )
+            ret = confirm_overwrite(GTK_WINDOW(dlg), &yki);
+
+        if ( ret )
+            ret = gpgutil_open_file(file, "r", &in, error);
 
         if ( ret )
             ret = gpgutil_open_file(yki.output_filename, "w", &out, error);